Control device for automatic stokers



Aug. 7, 1934. w. T. HANNA CONTROL DEVICE FOR AUTOMATIC STOKERS Filed July 10. 1929 4 Sheets-Sheet 1 b \w 7 vw E Q hm R l y M \l o .l J 2 T I II v a A... NN m a 0 @Q Q (N & QN

IN VENT OR A TTORNE Y5 Aug. 7, 1934. w. T. HANNA 1,969,265

CONTROL DEVICE FOR AUTOMATIC STOKERS Filed July 10, 1929 4 Sheets-Sheet 2 lmiwi.

w a w \x JWZ WK INVEN OR A TTORNE Y5 Aug. 7, 1934. w T, HANNA 1,969,265

CONTROL DEVICE FOR AUTOMATIC STOKERS Filed July 10. 1929 -4 Sheets-Shed s miim by I 6 1 M A TTORNEYS Aug. 7, 1934. w. T. HANNA 1,969,265

CONTROL DEVICE FOR AUTOMATIC STOKERS Filed July 10. 1929 4 Sheets-Sheet 4 WM MM GM* m ATTORNEYS Patented Aug. 7, 1934 CONTROL DEVICE FOR AUTOMATIC STOKERS William Thompson Hanna, Cincinnati, Ohio Application July 10, 1929, Serial No. 377,082 3 claims. (or. 121-141) This invention relatesto stokers for use on locomotives and the like but more particularly to controlling mechanism for the same.

One of the objects of the invention is to provide a simple and effective means for quickly and easily controlling the operation of a stoker.

Another object is to provide a stoker mechanism and power device which may be manually controlled by a single operating lever.

Another object is to provide a device capable of performing a plurality of functions such as controlling the speed and direction of the power device and the power delivered thereby.

.Another object is to provide means by which the power applied to the stoker or other mechanism is automatically increased when such stoker or other mechanism becomes overloaded or choked, and such power returns to normal in the same manner when this condition ceases to exist. Other objects will bein part obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangements of parts all as will be herein illustratively described, and the scope of the application of which'will be indicated in the following claims.

In the accompanying drawings in which are shown the features of a selected embodiment of this invention:

Fig. l is a side elevation partially in section.

Fig. 2 is a horizontal sectional view on the line 22 of Fig. 5.,

Figs. 3 and 4 are the same as Fig. 2 except that the parts are in different positions.

Fig. 5 is a vertical section on the line 55 of Fig. l and w Fig. 6 is a sectional view substantially on-the line 6-6 of Fig. 5.

Referring to the drawings, the stoker mechanism is shown in connection with the firebox of a locomotive in which the usual backhead 10 is provided with a. firing opening 11. About this opening is a fuel supply housing 12 which encloses the fuel elevating and distributing mechanism (not shown). This mechanism may be of any suitable character to cause the fuel to pass through the firing opening and be distributed over the fire box of the locomotive. Fuel may be conveyed to the housing from below the deck 13 of the tender in any suitable manner as by spiral conveyors 14 and 15, the former of which is revolubly mounted in the tender hopper 16 and operatively connected'to the latter by means of a universal joint 17. The

and slide blocks 44 and 45 in the usual mansimilar series-65. This valve series to control conveyor 15 is revolubly mounted in a housing 18 and its forward end is universally connected .at' 19 to the lower extension of the housing 1 below the deck 20 of the locomotive. The elevating. and distributing ,mechanis within the housing 12 and the transfer mechanism or conveyors 14 and l5-may be actuated in any suitable manner suchas'the-steam-actuated power device or motor 21. This device is mount.- ed upon the locomotive and operatively connected to the elevating and distributing mechanism by a telescoping shaft 22. It is likewise operativelyconnected to the transfer mechanism by a telescopingshaft 23.

The power device 21 may be of any suitable 761 character but for the sake of illustration I have selected a twin-cylinder steam motor of conventional type. This motor comprises a cylinder housing 24 in which are cylinders 25 and 26 (Figs. 5 and 6) and corresponding pistons 27 and 28 operating in the usual manner. Steam is supplied to these cylinders through passages 29, 30, 31 and 32 controlled by distributing valves 33 and 34 slidable in corresponding cylinders 35 and 36. Reciprocating valve rods 37 and 38 are connected to the valves 33 and 34 respectively and these are operated from the main crank shaft 39 through the mediuinrof eccentrics 40 and 41, rods'42 and 43,

ner.

On the cylinder housing 24 above the cylinders 25 and 26 is a manually operable control device 55. This device comprises a cylindrical control valve 56 slidably mounted in a cylinder 57 which is rigidly secured within the housing. The valve 56 comprises an operating rod 58 upon which are secured a number of sections, 59, 60, 61, 62 and 63, the whole making up the body of the valve. This construction of the valve is a matter of expediency and any other suitable form might be substituted therefor.

At the rear end of this valve 56 are a series of piston rings 64 and at its forward end are a the passage of steam to and from the valves 33 and 34; i. e., it throttles the steam flowing to the distributing valves 33 and 34 and throttles the steam coming from the valves in the manner to be presently described.

Manual control of the valve 56 may be eflected in various ways but in the present instance there is provided a control lever 75 fulcrummed at 76 upon the housing 24 and connected at 77 with the forked yoke 78 secured to the outer end of the rod 58. Movement of this lever '75 shifts the position of the valve 56 to control the direction of rotation of the power device, either forward or reverse, or renders this device inoperative. It also controls the speed of the power annular exhaust passage 83 by the port 89 through which the steam is ejected. Other similar passages as 84 and 85, are arranged within the housing and communicate with ports 8'7 and 88 respectively in the wall of the cylinder.

In Figs. 2 and 6 the valve 56 is in the position to cause the power device and the stoker mechanism to run forwardly. Steam enters the cylinder 57 through the pipe and the port 82, passing through the center of the valve 56 and through the ports 88 into the passage and then to the valve cylinders 35 and 36 through passages 90, the passage to the cylinder 35 not being shown in the drawings but being similar to the passage to the cylinder 36. From these valve cylinders 35 and 36 the steam passes to the corresponding power cylinders 25 and 26 by way of passages 29 and 32 respectively. The steam on the opposite side of the piston 27 is exhaustedat the same time through passages 30 and 31, ports 92 and 93, passages 94 and 84, ports 8'7 and 89, and passage 83 to the exhaust pipe 81. In the same manner the steam in the cylinder 28 exhausts through the passages 31 and 95, ports 96 and 97, passages 98 and 84, ports 8'7 and 89, and passage 83 to the exhaust pipe 81. With the parts in this position it is obvious that the engine willreciprocate in the usual manner.

To reverse the motion of the power device and the stoker mechanism, the lever '75 is shifted to bring the control valve 56 into the position indicated in Fig. 3. Here the live steam enters the cylinder 57 through the pipe 80 as before and passes into the passage 84 by way of the ports 87. It next travels by the passages 94 and 98 (Fig. 6) to the automatic valve cylinders 35 and 36 and then through the passages 30 and 31 to thepower cylinders. The steam on the opposite sides of the pistons '27 and 28 exhausts through the passages 29 and 32, the passage in the valve cylinder 36 and the corresponding passage in the cylinder 35, the passage 85, andthe ports 88 and 89 to the exhaust pipe 81.

In the position of the control valve 56 in Fig. 4, the ports 8'7 are closed but the ports 88 are slightly open. The steam enters the cylinders through the passage 85 as in the forward position described but the steam on the other sides of the pistons 27 and 28 cannot exhaust because of the closed ports 8'7. Thus the power device is stopped.

Positioning the valve 56 at intermediate points between those indicated in Figs. 2 and 4 will cause the power device to deliver less power and to operate at less speed thanwhen the parts are in the position of Fig. 2, thje amount depending on the location of this valve between these extremes. For example, if .the valvev is moved slightly -forward of the position shown in Fig. 2 so that the forward edge of the ring 65 is flush with the edges of the ports 88, the rings 64 will partially reduce the area of the exhaust ports 87 although there is no proportional reducing of the area of the ports 88. The effect produced by such an adjustment of the valve would be to proportionately restrict the passage of the exhaust steam and thus create a back pressure upon the pistons of the power device as the exhaust steam cannot pass out as freely as when the exhaust ports are fully open. This acts to reduce the power delivered by the power device although the pressure of the steam entering the cylinders remains the same. In other words the pressure differential existing on opposite sides of the'pistons is reduced and the cushioning efiect obtained by controlling the exhaust is increased.

However, as the movement of the valve 56 is continued to the left from the position just described, the intake ports 88 are also reduced in size, as are the exhaust ports 87; and thus, the intake steam is throttled. This throttling action tends to reduce the amount of steam or power delivered to the pistons and hence tends to slow down the engine. At the same time, the back pressure is changed a predetermined amount so that the net effect is to reduce further the pressure differential and to shift the range in which the pressure differential operates.

Of course, as the movement of the valve 56 continues, the exhaust ports 8'7 are eventually cut off ahead of the intake ports 88.

In the construction shown-it will be evident that the area of the exhaust ports'is never greater than the area of the intake ports but the area of the exhaust ports may be less than the area of the intake ports when the control valve is moved to reduce the speed of operation which is proportionate to the power being delivered by the power device. Any momentary reduction of this speed due to a sudden increase of the power required for operation of the stoker mechanism will automatically cause an increase in the powerbeing delivered by the powerdevice. Thus when the stoker mechanism becomes overloaded or choked, greater power will be provided until this condition-has been overcome as the full steam pressure on the boiler side of the piston is maintained, whereas the pressure on the opposite side thereof is reduced. For example, when the crushing device encounters a hard slaty lump, this may cause a momentary.

hesitation of the apparatus and, during this hesitation, the exhaust steam is escaping while the full pressure is acting upon the face of the piston. The reduction of the exhaust pressure or that on the rear of the piston, increases the differential of-pressure in favor of the live steam or that on the admission side of the piston, thus giving a higher eifective steam pressure which means greater power. This automatic increase of power eliminates the necessity of the operthetemporary stoppage. The usual manual increase by the operator results in a racing of the engine as soon as the obstruction is eliminated and this will continue until the steam pressure is again reduced to normal by the operator. Frequent increasing and reducing of the power in this way very materially interferes with the regular duties of the fireman and provides uneven delivery of the fuel.

ator increasing the steam pressure to overcome The power mechanism of the steam motor and the automatic valve construction have not been described in detail as the particular form shown is well known in the art and was selected merely for the purpose of illustrating the operation of the control mechanism. It will be seen that this control mechanism may be used in connection with other power devices.

It will be evident from the foregoing description that there has been provided a simple and effective means for quickly and easily controlling the operation of the stoker. The stoker mechanism and the power device may be manually controlled by a single operating lever. I'he power applied to the stoker will be automatically increased when the stoker mechanism becomes overloaded or choked and will automatically return to normal as soon as this condition has been overcome. The control device is. capable of performing a considerable number of functions such as controlling the direction of motion of the power device to cause the stoker to be operated either forward or reverse, rendering the power device inoperative, varying the speed thereof, and regulating the power delivered thereby in accordance with the demands of the stoker mechanism. The entire construction is of an essentially practical character and the several objects of this invention have been attained.

As many other embodiments may be made of the features of the above invention without departing from the scope of the invention, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. A steam engine comprising a cylinder, a piston operating in said cylinder, valve mechanism for distributing steam to and from saidcylinder, and means for controlling the passage of steam to and from said valve mechanism, including a housing having inlet and exhaust ports, and manually operable means in said housing for completely covering said ports in one position, and in another position for completely uncovering said ports, said manually operable means effecting a larger exhaust lap than steam lap, whereby in the intermediate positions between said positions the efiective exhaust area is always less than the effective inlet area.

2. A steam engine comprising a cylinder, a piston reciprocating in said cylinder, valve mechanism for distributing steam to and from said cylinder, and means for controlling the passage of steam to and from said valve mechanism, including a housing having inlet and exhaust ports, and a manually operable member in said housing, including means for completely covering said exhaust-port, and means for completely covering said inlet port, when said member is in a first position of adjustment, said means also completely uncovering said ports when said member is in a second position of adjustment, and an exhaust lap provided on said means for closing said exhaust port ahead of said inlet port whereby in positions intermediate of said first and second positions of said manually operable member a predetermined difference in pressure is maintained on the opposite sides of said piston.

3. In combination with a steam engine including a piston chamber, a piston operating therein, automatically operated valve mechanism for distributing the fiow of steam to and from said piston chamber, intake and exhaust steam lines leading to and from said valve mechanism, an inlet port in said intake line and an exhaust port in said exhaust line; manually operable means for varying the differential pressure between the opposite sides of said piston and for varying the range in which said differential operates including a valve coacting with the inlet port to control the intake steam, a valve coacting with the exhaust port to control the 

